High pressure oil valve for returnflow burners



1 1957 E. A. CUNNINGHAM, JR 2,809,799

HI IGH PRESSURE OIL VALVE FOR RETURN-FLOW BURNERS Filed Aug. 12, 1954. 2 Sheets-Sheet l INVENTOR.

l l I EDWIN A. CUNNINGHANLJR,

Oct. 15, 1957 E. A. CUNNINGHAM, .;R 2,809,799

HIGH PRESSURE OIL VALVE FOR RETURNFLOW BURNERS Filed Aug. 12, 1954 2 Sheets-Sheet 2 3 V INVENTOR.

fowl/v A. CUNNINGHAM JR 47 48 Arfys,

United States HIGH PRESSURE GIL VALVE FOR RETURN- FLOW BURNERS Application August 12, 1954, Serial No. 449,411

6 Claims. (Cl. 251-52) This invention relates to valves for handling high pressure liquids such as fuel oil for oil burners and more particularly to valves adapted for controlling the supply of oil to burners of the return flow type.

Some types of oil fired boilers require very high pressure oil supply, the pressure being of the order of 800 to 1000 p. s. i. more or less. The burners involved are of the return flow type, that is, the burners have a return conduit in which a control Valve is located and by means of which the rate of delivery of oil to the burners is regulated. If the valve is adjusted towards its closed position, the rate of oil delivery to the burners is increased but if the valve is adjusted towards open position, more of the oil flows to the return piping and less to the burners.

An object of this invention is to provide a valve that is particularly adapted for return flow type burners operating on high pressure oil supply of the order of 800 to 1000 p. s. i. more or less.

Another object of the invention is to provide a valve having means for actuating it from a regulating control force, such as air pressure, and for adjustably pre-setting the minimum oil flow delivery rate to the burners.

A still further object of the invention is to provide a balanced valve of the above type and which is provided with means for damping the valve against hunting.

Other objects of the invention will be apparent to those of ordinary skill in the art to which the invention pertains from the following description taken in conjunction with the accompanying drawings.

In the drawings:

Figure '1 is a more or less diagrammatic view of an oil burner of the return flow type provided with a valve arranged and constructed in accordance with an embodiment of the invention; and

Fig. 2 is a view in section of the control valve arranged and constructed in accordance with what presently appears to be a preferred embodiment of the invention.

In Fig. 1 of the drawings an oil burner is schematically illustrated. That burner is of the high pressure type, oil being supplied to it at pressures ranging from 800 to 1000 p. s. i. by means of a pump 2. Pump 2 delivers oil to the burners from a supply tank 3 through a suction pipe 4 and a delivery pipe 5.

The particular burner; illustrated is of, the return flow type, that is, the rate at which oil is delivered to the burner is determined by the amount of oil that is returned or by-passed through a pipe 7, a regulating valve 8 and a return pipe 9 which leads to the supply tank 3. The burners 1, it will be understood, have some resistance to flow of oil; therefore, if the resistance of the flow path through pipe 7, valve 8 and pipe 9 to the tank is less than the resistance to flow through the burners, more or less oil will be returned to the tank depending on the valve setting, and in. that way regulate the amountv of oil delivered to the burnersfor combustion. Valve 8 regulates the flow of return oil and therefore regulates the total flow of oil to the burners 1.

atom:

Valve 8 may be controlled automatically by means of a regulating pressure admitted through a fitting 10. The regulating pressure may be supplied by a regulator which responds to temperature, steam pressure,.or some other factor that is proportional to the rate of combustion required at any instant.

Valve 8 is illustrated more in detail in Fig. 2. y,

Valve 8 comprises a body 11 having an inlet port pipe 12 provided with a flanged coupling member 13 to which the return pipe 7 would be connected. The valve also includes an outlet port pipe 13 having a flanged coupling member 14 to which the return pipe 9 is connected. The valve body is provided with a cylindrical ported sleeve 15 having a flange 16 at its lower end by means of which the sleeve may be secured to the valve body. As shown, the sleeve is secured to the valve body by means of a ring plate 17 that is bolted to the underside of thevalve body by means of bolts 18, only one of which is shown.

A fluid pressure tight seal is formed between an inwardly projecting flange 19 on member 17 and the flange 16 of sleeve 15 by means of a sealing ring 20. The sleeve 15 is provided with a plurality of annular grooves 22, spaced lengthwise of the sleeve in which are disposed annular or ring-like sealing gaskets 23 in the form of 0 rings.

The sleeve 15. is provided with an inlet port 24 that communicates with the inlet port pipe 12 and an outlet port 25 that communicates with the outlet port pipe 13'. The sealing rings 23 are so spaced as to provide seals above and below the respective ports 24 and 25. As shown, the port 25 is spaced upwardly from port 24.

Within the sleeve 15 is a valve 26. Valve 26 includes an upper cylindrical portion 27 and a lower cylindrical portion 28 connected by a necked-in portion 28'. The portion 27 is provided with a plurality of spaced, annular grooves 29 and the portion 28 is provided with a plurality of spaced, annular grooves 30. The grooves 29 and 30 function as sealing grooves and also as pressure-equalizing devices for balancing the valve against unequal pressures. Portion 28 is provided with a passageway 28r which is relatively long and provides substantial resistance to flow of oil through it in either direction for a purpose described infra. Valve portion 27 is arranged to control the flow opening of port 25 and thereby control the flow restriction of the valve depending upon the position of the valve 26.

As shown in Fig. 2, the number of annular grooves 29 in the cylindrical portion 27 of valve 26, is greater than the number of annular grooves 30 in the cylindrical portion 28. As will be seeninfra, the open end of the bore in which portion 28 slides is in communication with a body of liquid confined in a liquid tight space, while the open end of the bore adjacent the end of portion 27 communicates with an open space under low pressure say atmospheric; therefore a greater resistance to flow past portion 27 must be provided, hence the grooves 29 exceed grooves 30 in numbers. As illustrated there are eight grooves 29 and three grooves 30. It is preferred that the ratio of number of grooves 29 to the number of grooves 30 be not less than 2:1 for pressures of the order of 800 to 1000 p. s. i.

The lower end of the valve 26 is connected to an adjustable tension spring 33 disposed within a cylinder 34. The spring is connected to portion 28 of valve 26 by means of a member 35 having a clevis 36 that registers with the lower end of portion 28 and is secured thereto by means of a through pin 37. Member 35 is provided with a flange 35' having a loose fit with cylinder 34 and with a threaded shank 39 upon which coils at the upper end of spring 33 are threaded. Coils at the lower end'of spring 33 are. threaded, on a stem 40 of a nut 41.. The nut 41 is provided with a bore 42 which is internally threaded to accommodate a screw 43. The lower portion of the screw 43 is provided with a flange or shoulder 44 that abuts the inner face of a member 45 that closes the lower end of the cylinder 34. The screw 43 is provided with a shank 46 that extends through the closure member 45: and is provided with a nut 47 which is secured to the stem 46 by means of a pin or set screw 48.

. The nut 41 is provided with radially extending fingers 49 and 50 that register in slots 51 and 52 in a guide sleeve 53 disposed Within cylinder 34, to prevent turning of the nut when screw 43 is turned to adjust the ten sion of spring 33.

The upper end of cylinder 34 extends into the flange ring 17 and abuts the flange I9, and is secured to the flange ring as by welding at 55 at the corner between the cylinder and flange 17. The joint between the closure member 45. and the lower end of cylinder 34 is sealed by means of welding asat 56. At spaced points 57 along the cylinder 34, the cylinder 34 is secured to guide sleeve 53 by welding, or other suitable means. By turning the nut 47 and therefore the screw 43, the nut 41 can be caused to travel along the screw 43 in either direction to adjust the tension .of the spring 33.

The closure member 45 is provided with a port 60 that leads through a passage 61 into the interior of cylinder 34. That port is provided with a valve 63. The upper end of cylinder 34 is ported at 65. Port 65 communicates with a port 66 in flange 17 to which is attached a fitting 67 having a valve 68. The cylinder 34 is filled with oil through valve 63, the valve 68 being open until it flows out of valve 68 free of air bubbles, at which time the valves 63 and 68 are closed thereby trapping oil in the cylinder 34. The oil in the cylinder 34 together with the restricted passage 28;- in the lower portion 28 of valve 26 and the annular grooves 30 therein, function as a dashpot to stabilize the valve by damping it and thereby preventing hunting of the valve when it is in operation.

The upper end of the valve body 1]. is provided with a diaphragm type operator 70 by means of which the valve 26 may be either manually positioned by a hand wheel or automatically positioned by means of a control pres sure.

The operator 70 includes a flanged cup-like member 71 that seats in an annular shoulder 72 of the valve body 11. The member 71 is welded to the body 11 as at 73. The member 71 is provided with a flange 74 and a bonnet 75 between which the marginal edge 77 of a diaphragm 78 is clamped. The bonnet 75 is secured to the flange 74 by means of bolts 79.

The central portion of the diaphragm 7Sis provided with an inverted cup-shaped backing member 80 and a stem or push rod 81 that extends through the central portion thereof and is welded thereto as at 82.

Member 81 extends through a plate 33 which is pulled down tightly on the central portion of the diaphragm by means of a nut 83a threaded on the member 81. Member 81 has a portion 84 extending into a socket 85 of a bonnet 86 that is welded to the bonnet 75, as at 87. Member 86 is internally threaded to accommodate the threaded portion 88 of a stem 89. As shown, the portion 88 is provided with a shoulder adapted to abut a shoulder 91 on member 36 when the stem 89 is turned outwardly to its maximum position. The joint'where the stem 89 passes into the member 86 is sealed by means of an O ring 90' or equivalent, retained in a groove 91 in member 86. The stem 89 is provided with a hand wheel 92 by means of which the stem and the portion 88 may be turned in or out of the member 86. By turning the member 88 into the bonnet 7d until the upper end of portion 84 engages the bottom of socket 85, the diaphragm may be pushed downwardly. Since the stern 8-1 extends into a socket 92 in valve 26 and engages the bottom of that socket, the valve 26 may be positioned by means of the hand wheel 92, if desired.

When the valve is on automatic operation the hand wheel 92 is turned until the threaded member 88 is in a position where the minimum oil flow to the burners is preset. Control pressure for automatically positioning the valve 26 is supplied through a port 94 to diaphragm 78.

In order that any leakage of oil past the portion 27 of valve 26 into the space under the diaphragm 78 may be scavenged, the housing member 71 is provided with a drain port 97. As shown in Fig. l, the drain port 97 is connected by a pipe 98 leading to the tank 3.

'In operation, the valve 26 is normally urged upwardly against the stem 81 by the unbalance of forces produced by the inlet oil pressure and the pressure of the oil transmitted to the dashpot through restriction 23r and acting upwardly on the cylindrical portion 28. When a control pressure is applied to the port 94, the force of that pressure acting on diaphragm 78 will move valve 26 downwardly to a position at which the restriction of port 25 will allow that rate of oil flow which is required by the control pressure. Since there is oil on the under side of the portion 28, being that contained in the cylinder 34, any downward movement of the valve 26 will displace oil in the cylinder 34 and cause it to slowly leak upwardly through the restriction 281' and the space about the portion 28. Likewise, if the valve is moved upwardly, a partial void space tends to form under the portion 28 which would be replaced by the leakage of oil from port 24 through the flow restriction 2dr. Thus it is seen that the valve 26 because of the oil in the cylinder 34 and the restriction 23F, is provided with a dash pot. The rate at which oil passes through that bore 28) determines the rate of interchange of oil between the cylinder 34 and the valve flow passage. The plurality of grooves 29 and 30 about the portions 27 and 28 of the valve provide relatively long leakage paths and therefore, eflective seals.

By adjusting the tension in spring 33 the unbalance on the valve tending to open it may be adjusted as required.

Having thus described the invention, it will be apparent to those of ordinary skill in the art to which it pertains, that various changes may be made in the illustrated embodiment without departing from either the spirit or the scope of the invention.

Therefore what is claimed as new and desired to be secured by Letters Patent is:

1. A high pressure valve for controlling the flow of liquid fuel through burners of the return-flow type comprising a body having a cylindrical open-ended bore therein, inlet and outlet ports spaced axially of and leading into and out of said bore, a valve in said bore comprising cylindrical portions and a connecting necked-in portion, one of said cylindrical portions controlling the outlet port and being provided with a plurality of spaced annular grooves forming a seal between the outlet port and the adjacent open end of the valve body bore, the other of said cylindrical portions being provided with a plurality of spaced annular grooves providing a seal between the inlet and outlet ports and the open end of the bore adjacent the inlet port, said latter cylindrical portion having a bore of relatively small diameter providing restricted communication from the space between the inlet and outlet ports to the open end of said valve body bore, a hollow cylinder secured at one end to said valve body with the interior thereof in communication with the valve body bore adjacent'the inlet port, means for closing the other end of said cylinder, means for filling said cylinder with liquid, means in said cylinder yieldingly urging said valve in one direction, said valve being urged in the opposite direction by the force applied thereto by liquid pressure in said cylinder as established through said restricted bore, and means for positioning said valve between closed and open positions, said cylinder and the restricted bore providing damping action for the valve to prevent hunting thereof.

2. A valve according to claim 1 in which the number of annular grooves in the cylindrical valve portion adjacent the outlet port is greater than the number of annular grooves in the other cylindrical valve portion by a ratio exceeding two to one.

3. A valve according to claim 1 characterized by the fact that means are provided for adjustably limiting travel of the valve towards open position.

4. A valve as in claim 1 characterized by the fact that a diaphragm operator is mounted on the valve body, the operator comprising a housing provided with a pressure actuatable diaphragm, the diaphragm being disposed to enage the valve and actuate it towards closed position against the pressure of the liquid flowing through the valve and acting thereon from within said cylinder.

5. A valve according to claim 4 characterized by the fact that means are provided for adjustably limiting the travel of the valve towards open position.

6. A valve according to claim 4 in which the diaphragm is provided with an inverted cup-shaped member disposed above the open end of the cylindrical bore in the valve body adjacent the outlet port to protect the diaphragm from direct flow of liquid through said adjacent open end of the valve body bore, said diaphragm housing having a 'drain port from which liquid escaping into the housing may discharge.

References Cited in the file of this patent UNITED STATES PATENTS 

